It is known that rubber latexes, especially nitrile-butadiene rubber (NBR) latexes can be directly reduced in the latex form to the saturated analog (HNBR) in the presence of hydrazine, an oxidizing agent and a metal ion initiator. Such reaction is disclosed in U.S. Pat. No. 4,452,950 to Wideman. Even with large excesses of hydrazine, reductions are not quantitative and there is a wide range, from 20% to 83% olefinic reduction, in the examples given. This patent states that the polymer be prepared in an aqueous emulsion polymerization and be reduced in the latex form without prior coagulation or use of organic solvents. Use of a surfactant in emulsion polymerization is standard procedure and it is believed that an anionic surfactant as used, even though surfactant is not mentioned. This patent and the instant application are commonly assigned.
Hunig et al "The Chemistry of Diimide", Angewandte Chemie. International Edition, vol. 4, no. 4, April, 1965, pps. 271-280, describes methods for generating diimide (which this reference refers to as diimine) and to reactions of diimide with compounds containing one or more carbon-to-carbon double bond. Also described are decomposition of one mole of diimide into nitrogen and hydrogen, and disproportionation of two moles of diimide into nitrogen and hydrazine (these are competing reactions, as disclosed in the reference). Substrate specificity of hydrogenation, (i.e. multiple bonds which do not react with diimide) and competition between olefin hydrogenation, and between disproportionation and olefin hydrogenation, are also described. Reactions described were carried out in solution.
Organic Syntheses, collective vol. V, H. E. Baumgarten, Editor, John Wiley & Sons, Inc. 1973, pp 281-290, describes reduction of cis,trans,trans-1,5,9-cyclododecatriene to cis-cyclododecene with hydrazine and air in an ethanol solution containing copper sulfate. Product recovery includes filtration, extraction of the filtrate with petroleum ether, and distillation. A yield of 64-80 percent and a purity of about 80-90 percent are reported.
Organic Reactions, vol. 40, L. A. Paquette et al., Editors, John Wiley & Sons, Inc. 1991, pp 91-155, is a compilation of previously published procedures for generation of diimide and for reaction of diimide with compounds containing a carbon-to-carbon double bond. Relative reactivity of double bonds, stereoselectivity, and groups (such as N--O) which can be reduced with other reducing agents but not with diimide, are also noted. This article contains a number of specific experimental procedures, (all taken from earlier published literature) showing reduction of various substrate compounds containing carbon-to-carbon double bonds with diimide. Reduction of a number of additional substrate compounds is shown in tables. Reactions are carried out in solution, using organic solvents for the most part. The reference notes the need to use large excesses of diimide, owing to disproportionation and other side reactions.